Research Programme on Seismic Performance of Reinforced Concrete Walls: Key Recommendations

Abstract

A wide range of reinforced concrete (RC) wall performance was observed following the 2010/2011 Canterbury earthquakes, with most walls performing as expected, but some exhibiting undesirable and unexpected damage and failure characteristics. A comprehensive research programme, funded by the Building Performance Branch of the New Zealand Ministry of Business, Innovation and Employment, and involving both numerical and experimental studies, was developed to investigate the unexpected damage observed in the earthquakes and provide recommendations for the design and assessment procedures for RC walls. In particular, the studies focused on the performance of lightly reinforced walls; precast walls and connections; ductile walls; walls subjected to bi-directional loading; and walls prone to out-of-plane instability. This paper summarises each research programme and provides practical recommendations for the design and assessment of RC walls based on key findings, including recommended changes to NZS 3101 and the NZ Seismic Assessment Guidelines.

System overstrength factor induced by interaction between structural reinforced concrete walls, floors and gravity frames: Analytical formulation

“…Therefore, any possible source of overstrength in a building should be taken into consideration in capacity design. While amendments to several aspects of current NZ design and detailing provisions for structural RC walls have recently been recommended [11], the requirement to account for the aforementioned system interaction was not included in these recommendations.…”

“…When the curvature at the wall base equals the effective yield curvature, the deformed shape of the wall is shown in Figure 13(a). In this configuration, the vertical displacements at the left (tension) and right (compression) edges of the wall at each storey level are estimated by following the steps listed below,  Calculate the effective yield curvature yeff at the base section using Equation (11) or Equation (13).…”

“…This has led to more research [on RC walls with an aim to better understand and improve the seismic performance of RC walls [6][7][8][9][10]. These efforts have resulted in evidence-backed recommendations on improved design procedures for RC walls [11][12][13][14]. Nevertheless, these recommendations address issues related to seismic performance of isolated RC walls.…”

Numerical Investigations on the Residual Capacity and Economic Losses of Earthquake-Damaged Reinforced Concrete Wall Structures

“…Niroomandi et al [18] experimentally investigated the effects of the bi-directional loading on the seismic behavior of slender rectangular RC walls. An overview of comprehensive research programs, developed in New Zealand, following the 2010/2011 Canterbury earthquakes, and including practical recommendations for the design and assessment of RC walls, is available in Shegay et al [19]. Li and Xiang [20] suggested a formulation for assessing the effective stiffness of RC squat structural walls by performing a comprehensive parametric study.…”

Experimental study on the effects of bi‐directional loading pattern on rectangular reinforced concrete walls

“…Following the 2011 Christchurch earthquake, a large number of experimental 12,[28][29][30][31][32] and numerical studies [33][34][35][36][37][38] have been conducted in New Zealand to better understand the behavior of rectangular RC walls under seismic loading. The outcomes of these studies have led to a number of recommendations 39 to improve the design of rectangular RC walls. This paper investigates some of the concerns regarding the effects of bi-directional loading on this type of wall.…”